The looming restrictions will block trading of precious metals, steel, coal, currency and debt, as well as Iran's purchase of US dollars. The sanctions are expected to further slow Iran’s already faltering economy, and that’s before a further round of US restrictions target Iran’s oil, energy and shipping industries in November. The value of Iran's rial on the open market has plunged in recent weeks and Iranian authorities have banned the import of 1,400 items in an attempt to stop the outflow of hard currency while protecting domestic producers - which has only inflated the prices of certain imported goods. Many Iranians have withdrawn their savings and ploughed them into gold, dollars, property and cars in an effort to shore up their assets.

Iran's mounting economic challenges present a stern test for President Hassan Rouhani. Having already faced brusque opposition by conservatives unhappy with his stewardship of the government, recent protests in Khorramshahr and Tehran’s Grand Bazaar have left him with little room for manoeuvre. Unemployment across all working-age ranges stands at 12 percent, while youth unemployment is above 28 percent. Billions have been spent in support of President Bashar al-Assad in Syria's war.